1. Field of the invention
The invention relates to a method of joining a metal member to a resin member.
2. Prior art
The prior art to which this invention pertains includes a method of forming a rough surface on a metal member by means of etching, honing, applying molten metal, and so forth before resin is laminated thereon. In some cases, adhesive is employed to bond resin layers.
However, it has been pointed out that in the conventional methods, the joining strength between the rough surface and the resin is not sufficient.
A conventional method of joining a resin backing to a metal mold body developed by electroforming is discussed hereinafter to illuminate the problem of the prior art. The following is a manufacturing method of an electroformed mold. Firstly, a thin silver film a few microns thick, which provides conductance, is deposited by silver mirror reaction on the surface of an electroform matrix. The electroform matrix is then immersed in nickel plating solution. Secondly, the electroform matrix is connected with the anode of an electrical source while the nickel material for plating is connected to the cathode of the electrical source. Then, a predetermined level of electricity is loaded between the electrodes to deposit a metal layer on the electroform matrix, thereby forming a metal mold body. Further, backing resin is injected into or laminated on the metal mold body to obtain an electroformed mold reinforced by laminated resin on the back thereof.
This method, however, has a problem that the backing material for reinforcement easily separates from the metal mold body due to deformation caused by external heat or force. As the resin backing tends to separate from the metal mold body, the resin is unreliable as a reinforcement backing material. Hence, the metal mold body must be made thick.